Phonograph needle



All@ @E w. H. HUTTER 2,4%307` -PHoNoGRAPH NEEDLE Filed ct. 2s, 1943 Patented ug'. 6, 1946 UNITED STATES PATENT-orner.

8 Claims.

My invention relates generally to phonograph needles and in particular to a phonograph needle which possesses a very high reproduction fidelity and long life, and which minimizes record wear.

Although it has always been an object of those concerned with the development of the phonograph and the record reproducing art to provide a phonograph needle having the above characteristics, so far as I am aware, all currently used needles incorporate compromises. In general, little attempt has been made to save the record from wear when long needle life or high fidelity was desired, because it has been thought that the characteristics of long needle life and high fidelity were incompatible with long record life, and that one must be sacrificed to gain the other.

Under ordinary circumstances of record usage it is desirable to have both the record and the needle last as long as possible while retaining a high degree of reproduction fidelity. So far as I am aware, however, no needles presently obtainable incorporate these desirable characteristics to the same degree as the needle forming the subject of the present invention. As an example, all hard tip needles that I have tested, capable of playing from one thousand to four thousand records, seriouslyr affect the fidelity of records in from fifty to one hundred plays, while under actual conditions my improved needle plays the same record fteen hundred times before the iidelity of the record is affected.

Up to the present time it has been thought that for a phonograph needle to have high fidelity characteristics it must necessarily be very stiff and hard. This belief is based upon the desire to avoid needle resonance, one of the primary causes of sound distortion. Needle resonance is the inherent needle vibration superposed upon the vibration picked up from the record. This causes the pure tone of the record to be muddied and to be amplied out of proportion within the range of the needle resonance-usually at high frequencies. These stiff needles, however, wear out the record surfaces comparatively rapidly, and the tone then becomes fuzzy and scratchy. This effect is particularly apparent when such needles are used with automatic phonographs, wherein the records are played over and over again without the attention of an operator.

This condition led to the development of the flattened section in the spike type of needle in an attempt to reduce needle and record wear. Such needles are comparatively successful in that they reduce wear on the record and, therefore, extended its life to some extent. They are far from perfect, however, because they do not remove needle resonance, and the sharp edges bounding the connection of the flattened section with the barrel section of the needle tended to filter out .the high tones. Such needles reduce record wear because they are flexible in one direction, that is, in a direction perpendicular to the plane of the flattened portion. But as this flattened portion is always perpendicular to the surface of the record, there is no vertical flexibility inherent in such a needle.

When it is realized that there is a tremendous pressure applied to the tip of a needle, it will be appreciated that rapid wear will result unless some means is provided to ease the pressure when the record tends to cause rapid vertical changes in the position of the pickup. Ordinarily, a phonograph needle used with a two ounce pickup imposes a load of approximately thirty-one thousand pounds per square inch upon a record surface. It is apparent, therefore, that some relative wear between the needle and record must be expected. In order to introduce flexibility inv all planes, so as to protect the record against up and down as Well as lateral shocks, some needles have been developed which are flexible in all directions, but in all of these prior art needles with which I am familiar, a shoulder has been provided between the flexible portion and the stiff portion of the needle, and this shoulder filters out the high tones and destroys the fidelity of reproduction.

My improved phonograph needle provides for flexibility in all directions, while at the same time retaining fidelity of reproduction to a greater extent than any prior needles with which I am acquainted.

Still anotherproblem is caused by the fact that a record groove does not have a constant width, but at those points where the groove makes a sharp angle relative to the radius of the record, the transverse dimension is less, and thus, there is a pinching effect. The pinching effect tends to force the needle and the pickup upwardly. Because of the high pressure applied to the tip of the needle, as has heretofore been pointed out, the record groove at these places is worn to a greater extent than the groove at the wider places and, therefore, record wear is accentuated at these points. My improved needle, because of its flexibility, is not required to move the pickup rapidly to any great extent ina vertical direction and thus, the record wear at these points is minimized. The flexibility of my needle also permits the easy and accurate tracing of the needle through the groove at those points where the direction of the groove changes sharply, il e., where an explosive sound occurs in the recording.

It will be apparent from the above that prior needles do not effect a solution to the real problem faced by the phonograph and record reproduction art, but in general compromisein favor of long life in theneedles at the expenseof the recordings.

In my experiments with phonograph needles I have discovered that the' compromise Vbetween the present invention ,possesses extremely. high..

ndeiity and1qng4iife-characterisncs orb'otheedie and record.

I have combined these desirable qualities in one needle by shaping it in such a manner as to give it a iiexing and cushioning action du1f ing-, itsY travel in the record groove, which action copi-- pensates for variations in the groove width and assists in properly controlling and overcornipgtha inertia in the tone arm and pickup. I have also eliminated objectionablewneedle resonance by giving that portion of the needle below what I term the fulcrumv `a. shape. which willJ nothave naturalresonance withinthe audi-ble range; the.

material from which-the-needle ismade-.also assists f in eliminating. needle resonance.

From the foregoingit is L.clearly apparentthatit is an object of my invention to provide anim.-Y provedphonograph. needle which possesses a high reproductiondelity and also long life, andwhich does not wear .the record surface with Which-the needlemay be. used to any appreciable extent when comparedv with priorart needles.

Itis alsolan object ofY my Ainvention vto provide a novell .phonograph needle possessing the 4desirable characteristics fof. high .delity andv 4long life both-ofthe needleand the record. and which is economical to manufacture.

Other objects and advantages will become apparent from y the following description taken in conjunction with .the drawing, in which Fig. l *isa` greatly enlargedielevational view of a preferred embodiment of inyimprovedf and novel phonograph `needle and;

Figs. Zand 3 .illustrate modied andimproved formssof phonograph needle Shanks- Referring to Fig. '1,- my-Aimproved phonograph needle I maybe Vdivided -into three sections `for convenience of referenceand description of function. The needle is formedofconical andcylindrical integral sections and its diameter is greatest at shank-portion I2 which is `received by-v the needle chuck in a manner'well knowninthe art.; Connecting the shank portion I2-w-ith-end portion Ill is a tapered sectionV I 6V. At the-lower end of the end portion I4 -is a long-wearing, hard alloy tip I8,- which is preferably welded -to theY portion Iii.A

The tip I8 is extremely small and possesses aY rounded `end having a radius of curvature preferably not greater than 0.002 inch: Abovethe tip I8 the lowerend of the portion I4 is tapered down to the. tip at anincluded angle of between 25O and 60.

It will be noted from the `drawing that the long.- est of these sections is the tapered section I6;v It is well known in the needle art that the danger point or needleY resonance lies between thefulcrum point and the tipcontacting theY record. 1 Itn this portion be of a length sufcient vto beoperable and act as a lever to transmit the vibrations from the record to the pickup, then it necessarily is of suiiicient length to possess periodic resonance within the audible range; and if'this needle be of constant diameter throughoutthegreater part of its length below the fulcrum; the tendency/toward needle resonance is enhanced.-` Buti-this portion ofthe needle beof aconstantly-changing diameter presenting a Vregular taper, the resonance of the needle at each point on the-tapered section i is different and` whateverA4 resonance. is

possessed byfthe needle int-hat section` is damped l that this portion of the needle be made as small as is compatible with the strength necessary to supporttheeiective weight of the pickup and tone arm and to absorb the thrusts which are imposed-upon it by the vibration and the oscillating groove for operating mechanical trip means frequently` usedAA toy set y automatic. record changing mechanism -into operation-.fA

Because thetip 4section I4i'is .of comparatively small diameter; itfhas aspringy or cushioning. action -whiclr permits it to follow.- the. groove. .in

the record.` accurately and. whip.- around `the sharp angles corresponding to i the, .explosivesounds.; Probablythe major. portion` of. this .cushioning or springing action takes place at .theljunctioniliofe.`

the tapered "section I6.; with portion.. IM The cushioning or-springing action of. theiend section is of the universal Vtype and permits the needle .tof follow the record .grooveac'curately and; continuously. At vthe narrowest points where.. the groove pinches theneedle and. impartsatendency to ride out, the cushioning-actioncompensates for` the inertia .of -theftone arm and. thepickup, therebyr minimizing record wear,` andV consequently record scratch; The vend. section I4 possesses-no needle -.resonance,f or.- atleast none *.within the`- audible range, because off its short-:length andl low mass.-v

It I willalso appear from the drawingf-thatemy improved phonograph' needle vis f slightlylongerU than most prior.. art needles. 'Iheaincr'easedr` lengthis further important tomaintainlfidelity and long record wear `-inthose passages f where whip action is imparted tothe needle as it passes around the. sharper angles ofagroove sinceless pickup weight will I suffice to prevent f groovel jumping4 or chattering-when` thisilexibilityds present. y.

It is important to note therapproximate relativesizes ofthe shank I2,l the tapered section IB-ian'd.- end portionvv I4.: The combined -lengthof the por nous man@ ls iisgreater than .that oftneshak l I2 to provide a lever below the ralorum-which# will transmit more accuratelyethe vibrationspicked Vupfrorn the record. The'positioning-of the hinge or junction 20-between the -tapered-` section II,` and the'end portion I4-must-be suchf that the reactance'ofe-the' needle -is substantiallyA less thai-the reactance Vofthe pickup. if'

the portion I 4 betooshort-withrespectto the vsection I6, the needle .compliance would betoo little and the effect ofthe hinging orcushioning action-would be completely lost.;Y `On the other.

hand; if the portion I4 be wtoo \long, theltapered section I6 must be appreciably shortened,which .would result in a needle having too `much ilexibilityvor compliance, andthe taper'wouldfbeso-- great that an appreciable percentage-of the highV pitch tones thaving shorter yperiods of vibration would -belteredoum and because of theexces-v .siveflexibilitm some of thebase tones would also be lost. As exemplitive ofa'typicalneedle -embodying my=invention, the guresin -thelaccom panying, drawing.are.made to scale.. The-totallengthY ofthe `needles illustrated is actually three-- .5 VI' 2 is one-quarter of an inch; the dimension .B, the length of the tapered section, five-sixteenths of an inch; and dimension C, the length of the tip portion I4, is three-sixteenths of an inch (including the tip I8). The shank has a diameter D of 0.061 inch, and the end portion III has a diameter d of 0.029 inch. It is thus seen that the tapered section is nearly twice as long as the end portion I4 and that the shank is only one-third of the entire length of the needle. These proportions appear best for ordinary use, but may be modified if the compliance and resistance ratios of the pickup are known accurately. If it is found necessary to shorten the over-all length of the needle, I have found that the reduction may be made by shorteningr the shank portion I2 the requisite amount, retaining the relative length of the sections Ill and I6.

In order further to reduce needle resonance, I prefer to make my improved needle from a soft steel having high internal resistance. As an example, I have found that a steel possessing a Rockwell hardness of is ideal for the manufacture of my needle. It is also possible to manufacture my improved needle from other metals or metal alloys which possess the same desirable characteristics.

In Figs. 2 and 3 I have illustrated a further modification of my improved needle in which the shank I2 is formed in a manner to prevent relative angular and longitudinal movement between the needle and the chuck when secured by the chuck set screw. It has heretofore been the practice to provide the shank with a flattened section to be engaged by the set screw, but the flattened section has the deleterious effect of acting as a lter for the higher audible tones. I prefer to form the shank I2 of my needle with longitudinal or crossed knurling. Fig. 2 showsv longitudinal knurling 2li, and Fig. 3 shows crossed knurling 26. Forming the shank in this manner has no effect on the transmission of the recorded vibrations and provides a good surface to be engaged by the tip of the set screw.

From the foregoing description of my invention, it will be apparent to those skilled in the record reproducing art that I have invented a phonograph needle which successfully combines high fidelity of tone reproduction and long needle life with long record life. This is accomplished through the use of a longer and more flexible needle having a cushioned or hinged action and which is shaped to remove needle resonance, and through a choice of material, to assist in reducing resonance.

In view of the fact that persons skilled in the art can, from the teachings of the present specication and drawing, make changes without departing from the spirit and scope of my invention, I desire to be limited only by the appended claims.

What I claim as new and useful and desire to secure by United States Letters Patent is:

1. As a new article of manufacture, a phonograph needle having a shank, a cylindrical end portion having a diameter less than the diameter of said shank, andY a substantially conically shaped tapered portion connecting said shank with said end portion and integral therewith, said tapered portion merging at either end with said shank portion and said end portion respectively.

2. As a new article of manufacture, a phonograph needle having a shank, a cylindrical end portion having a diameter less than the diameter of said shank, and a substantially conically shaped tapered portion connecting said shank with said end portion and integral therewith, said tapered portion being longer than said end portion and merging at either end with said shank portion and said end portion, respectively.

3. As a new article of manufacture, a phonograph needle having a shank, a cylindrical end portion having a diameter not greater than onehalf the diameter of said shank, and a tapered end portion connecting said shank with said portion and integral and merging with both, said tapered portion being longer than said end portion, and the angle included by the surfaces of said shank and said tapered portion being not less than Il. As a new article of manufacture, a phonograph needle having a shank, a cylindrical end portion having a diameter not greater than onehalf the diameter of said shank, and a tapered portion connecting said shank with said end portion and integral and merging with both, the ratio of the length of the tapered portion to the length of the cylindrical end portion being of the order of 5 to 3, and the angle of taper being substantially 3.

5. As a new article of manufacture, a phonograph needle made from soft steel and having a shank adapted to be received by a pickup, a tip formed of a long wearing, hard alloy adapted to follow in the groove of a record, and an intermediate portion connecting said shank with said tip and having a point of greatest flexibility therein, said point of greatest flexibility being closer to said tip than to said shank, the upper part of said intermediate portion being tapered so that it merges both with said shank and with the lower part of said intermediate portion, said lower part being of a lesser diameter than said shank.

6. As a new article of manufacture, a phonograph needle made from a metal or metal alloys having a high internal resistance and having a shank adapted to be received by a pickup, a tip formed of a long wearing, hard alloy adapted to follow in the groove of a record, and an intermediate portion connecting said shank with said tip and having a point of greatest flexibility therein, said point of greatest flexibility being closer to said tip than to said shank, the upper part of said intermediate portion being tapered so that it merges both with said shank and with the lower part of said intermediate portion, said lower part being of a lesser diameter than said shank.

7. As a new articleof manufacture, a phonograph needle having a shank, a cylindrical end portion and a tapered portion connecting said shank with said end portion and integral and merging with both, said shank having a knurled surface adapted to be engaged |by a needle retaining means to prevent relative angular and longitudinal movement between the needle and the needle retaining means. y

8. In a phonograph needle having a shank, a tip adapted to follow in the groove of the record and an intermediate portion connecting said shank with said tip and providing a point of maximum flexibility therein, which point is equally flexible in all directions, a knurled surface formed on said shank adapted to be engaged by a needle retaining means to prevent relative angular and longitudinal movement between the needle and the needle retaining means.

WILLIAM'I-I. HUITER,

Certificate of Correction Patent No. 2,405,307. August 6, 1946.

g WILLIAM H. HUTTER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 6, line 1l, claim 3, strike out end before portion and insert the seme after said second occurrence, same line; and that the said Letters Patent should be read With this correction therein that the same may conform to the record of the oase in the Patent Oce.

Signed and sealed this 5th day of November, A. D. 1946.

LESLIE FRAZER,

First Assistant 'ommz'ssz'oner of Patents. 

